Nanocellulose, or nano-structured cellulose, comprises cellulose particles or fibers which have been exfoliated from cellulose fibrils using either mechanical or chemical means. The “nano” portion indicates that at least one dimension is measured in nanometers. This is in contrast with other fibers having similar geometry that are formed by dissolving the cellulose and regenerating it. Nanocellulose materials can be derived from wood, algae, plant or bacterial sources.
Due to its relative strength, especially in terms of strength/weight ratio, viscosity, and other mechanical properties, nanocellulose can be used for many applications. Some of the applications for nanocellulose include fillers for food products, paper towels or other paper products that benefit from increased absorbency, reinforcing plastics, medical and pharmaceutical applications, as well as multiple other applications.
Similar to nanocellulose, hydrogels of alginate, starch, polymers or cellulose can hold a significant amount of water. Hydrogels are cross-linked polymers which are well known in the art to hold large amount of water. For this reason, hydrogels are often used in situations where it is important to maintain a certain level of saturation and/or absorption. One application of hydrogels is for a dermatological mask, where hydrogels' water retention capacity, coupled with or without the inclusion of dermatological agents, enables the application of a saturated hydrogel mask to a user's skin. Unfortunately, such masks have a low degree of conformability to the skin and are not porous. The lack of porosity limits the absorption of dermatologically active ingredients by the skin.
In addition to cross-linked alginates, nonwoven sheets with dermatologically active ingredients may be used for dermatological masks as well. Such nonwoven sheets are usually made from long fibers bonded together using chemical, mechanical, heat, or solvent treatments. A flat, porous sheet is typically formed using this method. Nonetheless, conventional systems are not optimized for efficient production of nonwoven sheets with even dispersion of active ingredients or controlled formation of porous sites.
Therefore, in view of the aforementioned difficulties, there is an unsolved need for methods and systems for efficient production of hydrated, nonwoven dermatological sheets capable of transpiring or evaporating water through, thereby causing a dynamic fluid system between the skin beneath the sheet and the sheet itself. In addition, it would be an advancement in the state of the art to incorporate particulates and solution-based active ingredients for even dispersion throughout the formed sheets.
It is against this background that various embodiments of the present invention were developed.